Longitudinal study of bone turnover after acute spinal cord injury.
Increased bone turnover is a sequel of spinal cord injury (SCI) and predisposes to a number of clinically relevant complications, including osteoporosis and fractures. There are limited data available regarding the changes in modern markers of bone metabolism after SCI. We report a 6-month longitudinal follow-up of biochemical markers of bone metabolism (free and total deoxypyridinoline, total pyridinoline, N-telopeptide, osteocalcin, and total alkaline phosphatase) and bone mineral densitometry in 30 subjects with acute SCI. Markers of bone formation showed only a minor rise, remaining within the reference range. In contrast, markers of bone resorption showed a significant rise after acute SCI, peaking around weeks 10-16, with values up to 10 times the upper limit of normal. Paired bone mineral densities (n = 11; on the average, determined 14 weeks apart) showed no change at the hip, lumbar spine, or radius, but demonstrated a decrement in the entire lower limbs. changes in biochemical markers of bone formation and resorption were comparable in patients with quadriplegia and paraplegia, except for a greater increase in quadriplegics in pyridinoline, expressed as a percentage of baseline. In conclusion, a marked increase in bone resorption and modest changes in bone formation occur after SCI, and possibly increased bone resorption occurs in quadriplegia.
Roberts
D
D
Department of Chemical Pathology, Princess Alexandra Hospital, Woolloongabba, Queensland, Australia. davidr@australiamail.com
Lee
W
W
Cuneo
R C
RC
Wittmann
J
J
Ward
G
G
Flatman
R
R
McWhinney
B
B
Hickman
P E
PE
D000293:Adolescent; D000328:Adult; D000596:Amino Acids / Q000652:urine; D015415:Biomarkers; D015519:Bone Density; D016723:Bone Remodeling; D001862:Bone Resorption / Q000503:physiopathology; D002117:Calcitriol / Q000097:blood; D002118:Calcium / Q000097:blood / Q000652:urine; D003094:Collagen / Q000652:urine; D024042:Collagen Type I; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010264:Paraplegia / Q000503:physiopathology; D010455:Peptides / Q000652:urine; D011446:Prospective Studies; D011782:Quadriplegia / Q000503:physiopathology; D013119:Spinal Cord Injuries / Q000503:physiopathology*
D000596:Amino Acids; D015415:Biomarkers; D024042:Collagen Type I; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; C015484:pyridinoline; C036020:deoxypyridinoline; D003094:Collagen; D002117:Calcitriol; D002118:Calcium